The present invention relates in general to video displays, and pertains, more particularly, to a video mixing system that provides the capability of processing more than one type of video signal at the same time.
For some particular display applications, it is desirable to display more than one video signal. This requires the mixing of video signals. Video mixing is usually carried out by using look-up tables employing RAM memories and with the additional use of circuitry such as resistors and transistors to control intensity levels. The basic problem with this approach is that it is relatively expensive and requires that the look-up tables be pre-programmed to accept the video signals as an address. The need for a storage RAM makes the system expensive. Also, additional space may be required for this approach which can pose a problem, particularly in applications having rigid space requirements.
Thus, it is an object of the present invention to provide an apparatus and associated method for performing video mixing while at the same time eliminating the need for expensive look-up tables and additional circuitry such as an additional RAM memory.
Another object of the present invention is to provide an improved video mixing system that is relatively simple in construction, that can be manufactured relatively inexpensively, and that provides for optimum video-graphic control.